Unhook both wires

 

Has anyone ever checked glow plugs outside of the engine. I checked resistance from tip to tip and it was 0.00. Has anyone ever stuck the plug end on top of the battery + side and connect a jumper to the threads and the negative side of the battery to see if it would heat up?

 

Of you hook jumper cables to. Your battery and the hook the ground to the body of the GP and the hot to the top tip it should get hot

 

bad12jr.

It spins real well. I have it hooked to 60amp charger when rotating just so it won't drop down. No difference when hooked up to the charger or not.

 

fordpride

Thanks, I thought it should get hot if it was grounded. I'll try that tomorrow and make sure my ground is good. Not positive on the test I ran today. The engine lift hooks are a little rusted and I didn't ohm out the ground to make sure it was good. Also, I will ohm out the wiring harness from the relay to the valve cover. I am thinking I either have a couple of bad gp's from new or the harness is shorting when hot? Unless the poppet issue.

 

how many miles on the injectors???...I had a cold start prob like this for 3 years...a rebuilt set of sticks from Rosewood Diesel fixed it proper...hth

 

When my engine was apart, I wanted to know if my glowplugs functioned before putting them back in. Hooked jumper cables to a good battery. Clamped ground to body of glowplug. Hooked positive to tip. Got red hot immediately. I guess thats why they're called glowplugs, huh.

 

Allright,

Here is the latest, scrounged the yard for tools after throwing them last time I worked on said beast.
Checked with amp meter (10 amp DC) and found passenger side pegging the meter when glow plug circuit energized. Disconnect the two connectors -one at a time- and both pegged the meter. The drivers side was dead. Checked resistance from GPR Relay to valve cover and had good resistance. Check the terminal from the Glow plugs at valve cover to ground and had resistance. Pulled the cover and removed each glow plug and test by using amp meter. Each one pulled over 10 amps individually and got hot immediately. So Glow plugs are good. Reinstalled GP's. I went ahead and changed the valve cover gasket since it was the one I didn't change last time due to a short to the injectors. I assume, even though the connector had 0.00 resistance from the connector outside the valve cover to the glow plugs and ground that this is the same problem. Maybe shorting once current is flowing? So after doing all this I was checking the GP Relay again and current is flowing; however, the to smaller terminals appear to have been reverse wired. I assume the PO (Previous owner) replaced the relay (it looks fairly new) and reversed the wires. However still had within .2 volts from the batt + side of relay large terminal to the other large terminal GP side. So shouldn't make a difference. After all this I fired up the beast and it started. HUH? The temp was warmer about mid 40's. Tonite should be around mid 20's so tomorrow morning will be the check to see if it works. If this doesn't fix it, then I am at a loss. I know the GPR works the GP's work the wiring inbetween around in etc is good. So if not GP circuit then has to be timing or ?

 

The GPR relay from what I understand and please correct me if this is wrong. I assume the relay was replaced for like for like and not a upgrade. The relay I have in there has the Large battery terminal toward the firewall driver side and the small terminal firewall passenger side is the one that energizes (12V DC) then shows no power after energized. This is due to the PCM grounding the circuit and flowing? The front passenger side large terminal is the GP side and the front driver small terminal is 12V hot when key is on. If someone has something different let me know.

 

OH and for kicks and giggles I added an extra engine ground from negative battery post and the Alternator bracket.

 

Neither circuit of the relay is polarized. As long as you have the small wire from fuse 22 on one small terminal and the PCM ground trigger wire on the other small terminal, and the bat+ wire on one big terminal and the wires to the UVCHs on the other big terminal, you're golden.

 

Thought so, since it was working the other way. Thanks...

 

If you are concerned about it not kicking on. Determine which wire is hot and leave it hooked up. Run a switch in the cab with a ground to trigger the relay on when you want. Then you know it's working.

 

SUCCESS!!!!!
The temps were less than 30 degrees and it fired right up. Thanks for the help everyone.
Looks like even though I had continuity on the valve cover gasket/harness it was shorting out under load to the glowplugs.